Suitable Dietary Protein/Lipid Ratio for Hybrid, Female Red Sea Bream Pagrus major and Male Black Sea Bream Acanthopagrus schlegeli in the Juvenile Stage, Compared with Red Sea Bream
Fisheries and Aquatic Sciences
To determine a suitable dietary protein/lipid (CP/CL) ratio in the early juvenile stages of hybrid porgy (F 1 ), female red sea bream (RSB) × male black sea bream, five diets with various CP/CL ratios-60/7, 55/12, 51/17, 46/23, and 41/28-were prepared and provided to juveniles in triplicate. At the smaller juvenile stage, F 1 , weighing 0.32 g, a significantly higher specific growth rate (SGR) and feed efficiency (FE) were seen with 60/7 and 55/12 diets. However, in RSB weighing 0.26 g, SGR and
... ing 0.26 g, SGR and FE were higher with the 60/7 diet than the other diets at 21°C. At the larger juvenile stage, F 1 , weighing 3.7 g, there was no significant difference in SGR or FE among the diets, but RSB weighing 4.0 g fed 60/7, 55/12, and 51/17 diets had higher SGR and FE than 46/23 and 41/28 diets at 24°C. Moreover, survival and apparent nutrient retention of F 1 at both stages were significantly higher than those in RSB. These results indicate that both F 1 and RSB weighing ca. 0.3 g require a higher dietary CP/CL than those weighing ca. 4 g. Additionally, F 1 in both trials showed the suitability of a lower dietary CP/CL than RSB, indicating that mass production of F 1 juveniles will be more economical than RSB.